Lens-grinding machine.



G. II. DAY LL L. W. BIIGBLE.

LENS GRINDING'MACHINE, APPLICATION FILED MAY 2, IQII.

2 SHEETS-SHEET 1.

M//TA/ESSES:

lzltened Muy 30, Mib.

G. H. DAY A; L. vv. BUGBEE.

LENS GHINDING MACHINE. APPLICATION FILED MAY 2,1911.

atented May 3Q, 191.6,

2 SHEETS-SHEET 2.

GEORGE H. DAY ANI) LUCIAN W. BUGBEE, OF SOUTHBRIDGE, MASSACHUSETTS,ASSIGN- ORS TO AMERICAN OPTICAL COMPANY, OF SOUTHIBRIDGE, MASSACHUSETTS,A

CORPORATION OF MASSACHUSETTS.

LENS-GRINDING MACHINE.

igieaeai.. j

Specification of Letters Patent.

Patenten Mayen, raie.

application inea nay 2, 1911. serial No. 624,600.

To all whom t 'may concern:

Be it known that we, GEORGE DAY and LUorAN W. BUGBEE, citizens of theUnited -ful Improvements in `LensGrinding Machines, of which thefollowing is a specification.

i lens grinding machines and is particularly intended for use inconnection with grindj ing toric and cylindrical lenses. j j

Our invention as applied togrlndlngl lenses of toric and cylindricalforms coil)-l prises a lower grinding tool or form, an upper grindingtool, means forv simultaneously reciprocating the upper tool vacrossthe'loviger tool intwo directions transverse toeach other, the resultantof which will cause a given point on the upper tool to travel^ 1n acurvilinear path across the face of the'r lower tool; arbitrary meansforfvarymgtheam- Aplitude of the reciprocations in one d1rection; meansadapted to progressively and automatically vary the path of thereciprocations relative to the center line of the lower grinding tooltransverse to the first reciprocations; arbitrary means for adjustingthe limits within which the automatic varying means operate; arbitrarymeans for regulating the transverse initial position of the uppergrinding tool; means for throwing the upper tool out of contact with thelower tool; means for securing the lower tool in position; means forsecuring the upper tool to the transverse reciprocating member in such away that the'upper tool will be lifted outA of Contact with the lowertool Awhen the transverse member is lifted;

means for causing the upper tool to engage the lower tool underpressure; means for securing the lenses to the grinding tools, andAmeans for maintaining parallelism between the axis of the lens and thecorresponding axis ofthe grinding tools. l

The principal object of our invention is to provide means whereby thereciprocations of the grinding tool in the. two directions may be variedindependently of each other and the curvilinear path of the uppertoolover the lower tool arbitrarily adjusted and determined upon.

Another object of .our invention is to provide a feed which willautomatically and progressively vary the path of the reciprocations inone direction relative tothe center line of the lower grinding tool.

Another object of our invention is to prolvide arbitrary means forregulating 'the automatic feed. y

:Other objects of our inventionare to provide means for positioning theupper tool on the lower tool; for holding the upper tool en the lowertool under pressure in such a way as Yto maintain the .parallelismof thelens andy grinding tools; for lifting thei1pper tool oif the ower toolvwhen the transverse reciprocating arm is lifted; for readily changingthe lower' tool; for throwing the upper tool out of contact withthelowerv tool when the'parts are operating, and for housing theoperating parts. t.

With these and other objects in View, the invention consists in thenovel construction and arrangement of parts hereinafter dep `of what isclaimed maybe made without departing from the spirit ofthe invention.

Similar numerals ofreference are em-A ployed to denote correspondingparts throughout the several figures of the drawings.

In' the accompanying drawings: FigureV I is a top or plan view ofthemachine with the top casing removed. Fig. II shows an end view of themachine with a part ofits casing broken to show internal arrangements.Fig. III is a transverse section through the lower tool showing thesecuring arrangements. Fig. IV is a longitudinal section through Fig.III. Fig. V shows a sectional detail view of the automatic feedarrangement taken on line V-V, Fig. I, shown to opposite'hand. Fig. VIis a plan or top view of Fig. V. Fig. VII is a seetion or side viewofthe upper tool holding arrangements. Fig. VIII is a detail elevationor side view of the upper tool holding arrangements. Fig. IX is an endView or ing the progressive variation of the path of the transversereciprocations by means of the automatic feed.

l`or convenience of description, motions or reciprocations in a lineparallel with the driving shaft of the machine will be referred to aslongitudinal, whereas those at right angles to this direction will bereferred to as transverse movements or reciprocations.

The mechanism of the machine is suitably mounted on a bed plate oriframe 1, and a housing or cover 2 is provided to protect as much of themechanism as practicable from the abrasive or grinding mixture which isemployed between the lensholding or grinding tools. The lower grindingtool 3 which is stationary `is held on a boss i on the frame 1 by-meansof dowel pins .5 and an interlocking cam 6 tting into a groove or recess7 in the under side of the tool 3. vThis interlocking cam may be thrownin or out of position by `means of a lever 8, or other suitable.mechanism as preferred. l The upper tool A9 is operatively connectedwith the main power or driving shaft 10 in such a way that it will bereciprocated in both a longitudinal and a transverse direction, theresulting path of which will be curvilinear as indicated in Fig. X.

The longitudinal reciprocating means will now be described: The power issupplied through a shaft 10 which is thrown in `and out of engagement inthe usual man ner by the fast and loose pulleys 24 and 25. A verticallydisposed screw gear 11 which is slidably keyed to the powerl shaft 10vmeshes with a horizontally disposed screw gear 12 which is suitablymounted in a sleeve 13 attached to the bed plate or frame l. In theupper face of the horizontal screw gear 12 is a slot-way 14 in whichslides a shoe 15, to which is pivotally connected a link 1G which is inturn pivoted at 1T to a rocking lever 18 which is pivotfed at one end tothe frame at 19 and at the other end to a block 2O secured. to andturning with the main power shaft 10 which is slidably mounted'in itsjournals. The shoe 15 is adjusted in the slot 14 in the horizontal gearby' means of a. Set bolt 21 or similar locking device, while the end ofthe rocking lever 18 which engages the block 20 is bifurcated 4or formedinto yoke having embracing arms which are provided with pins 22 slidablyfitting intoy a groove 23 in the block 20.

The mechanism transversely reciprocating the upper grinding toolwilinext be described: This mechanism consists of two parts, onetotransmit the direct reciprocations, and a feed vgear designed toprogressively and automatically change the path of the directreciprocations. The direct reciprocations are transmitted through aneccentric arm niego-ei centric arm 26 which is pivotcd 'on the drivingshaft 10 by means oftwo ecccntrics 27, the eccentrics being connectedwith the main body of the arm 26 by the bifurcated members-28, while thecuter end of the arm 26 is fashioned into a handle 29 by which thearnionay be lifted, pivoting about 'the shaft 10. /Tlie eccentrics 27are xedly secured to the shaft 10 and the shaft end of the arm QlisIdivided to forma. bearing around the eccentrics 27, said dividedmembersBO and 31 being held together in the usual manner by bolts. Theeccentrics 27 revolve with the sha-ft 10 and give atransversereciprocating motion to the eccentric arm 2G. The upper tool 9 isoperatively attached to the eccentric arm 26 through the connectingstrap which is pivoted to the arm 2G at 38 and carries at its lower enda pin 3l, the under end 35 of which is pointed to universally engage asocket 36 in the upper tool 9.

rlhe upper tool 9 is maintained in parallel alinenient with the lowertool 3 by means of spring forks 37 secured to the cross bar 88 which ispivoted on the pin 39 extending into the bloc-lr 40 which in turn ispivoted by the pins 41 to the rocking bracket 42 which is in turnpivotcd at 43 to the ec- The'spring el which is attached at 45 to theeccentric arm 26 and at 46 to the pivot pin 39 draws the spring forkstoward the eccentric arm 26 and consequently maintains the upper tool 9in con'- tact with the pin 34 in the arm 32. Pivot bearing points 47 areprovided on the spring fork 37 to fit into corresponding recesses in theupper tool 9 so that the tool 9 during the reciprocations of the arm 26will adjust itself to the curvature of the lower tool in one directionby means of the pivotal movement on the points i7 and in a. directiontransverse thereto by means of a corlresponding pivotal movement of thecross bar 38 on the pin. 39 secured to the block 40.

The upper tool 9 is progressively fed transversely across the lower tool3 by means, of the connecting rod i8, which causes the connecting strap32 to oscillate about its fulcrum The rod i8 is journaled on a slidebolt Sl-fitting in groove 50 in the head of a pivot bolt 51 vwhichextends thpgugha friction bearing 52 integrally formed on the dividedarm 28 of the eccentric arm 2G. On the pivot bolt 51 is mounted aratchet wheel in such a Way that its teeth engage pawls 5ft which arepivotally attached to an oscillating arm 55 which is also pivoted on thepivot bolt 5l and extends therefrom toward, and has its opposite enddivided to slidably embrace the shaft 10 about as shown in Fig. Y'. .Theend of the oscillating arm 55 which embraces the shaft 10 will remain inrelative position to that shaft as it turns,

'Whereas tlievend which is pivot-ed to the A 55; ciprocations will beWithin its limits between pivot bolt 51 will travel in a reciprocatingpath whose course is transmitted by the eccentrics 27 through theeccentric arm 26 to which thefriction bearing 52 is integrally secured.This differential movement of the two ends of the oscillating arm 55will cause an oscillation of the end to which the pawls A-are pivotedthrough an angle having its apex at the center of the pivot bolt 51.This oscillation will cause the teeth of the pawls 54 to engage theteeth of the ratchet 53 and advance it accordingly. This movement rwhichhas been transmitted to the ratchet wheel 53 will in turn be transmittedto the pivot bolt 51 in the head of which the slide bolt 49 isadjustably secured in the groove 50. If the bolt 49 is adjusted so thatits axis coincides withy the axis of the pivot bolt 51, there will be nolinear motion transmitted to the connecting rod 48, but if the bolt 49is adjusted to one side or the other of the aXis of the pivot bolt 51 aneccentric movement will be set up and the corresponding linear motiontransmitted to the connecting rod 48. The number of teeth in the ratchetwheel 53 may be selected as desired and by the use of two pawls thiswheel may be advanced one half the circular pitch4 of one tooth to eachrevolution of the shaft 10; as for example-if there were fifty teeth inthe ratchet wheel 53 it would require one hundred revolutions of thedriving shaft 10 to make one complete revolution of the pivot bolt 51.

In the diagram shown in Fig. X the curve shown as a solid lineyrepresents the curvilinear path of a point of the upper tool 9 acrossthe lower tool when there is no feed motion to vary the path oftransverse reciprocation; i. e., when the axis of the bolt 49 coincideswith the axis of the pivot bolt 51. The curve shown in dotted linesrepresents the progressive advance of the path of the transversereeiprocations away from the longitudinal center line of the lowergrinding tool when the automatic feed ygear is operating. In the diagramit will be unlderstood that the several 'transverse recipvrocations areshown as occurring during the period of a single longitudinalreciprocation, and also that the number of such reciprocations is forpurpose of illustration only and not necessarily correct. ',Iheprogressive addii.

vancement of the path of the transverse rethe parallel lines BB -BB;variation betweenthese limits being attained by one complte revolutionof the pivot bolt 51. The amplitude or the distance between the `linesA-Aand B-B may be varied by adof the grinding tools is worn more thanthe others, the position of the upper tool with respect to the lower maybe varied in a transverse direction by means of a shortening orlengthening device in the connecting arm 48. Iii the arrangement shownin Figs. I and II this device is formed by making the connecting rod 48in two parts and uniting them by a bolt 57 which has a right and lefthand thread connection" with the respective parts. Fixedly attached tothe bolt 57 is a head 58 which may be turned with a wrench or othei'tool so as to slierten or' lengthen the distance between the parts ofthe connecting rod 48. As the connecting 32 at 5G this shortening orlengthening operation will oscillate the connecting strap 32 aboutits'pivot 33 and change the position of the upper tool 9 on the lowertool 3 as desired.

The upper tool 9 may be lifted or thrown out of contact with the lowertool 3 either when the machine is idle or when operating, by means of anoffset crank 59 suitably mounted in its journals (30 on the frame of themachine. This offset arm is located under the eccentric ai'in 26and isthrown into engagement with that member by means of Va crank handle 6lsuitably located out of the 4tached to an eye (36 on the bedplate.

The lens to be ground is ordinarily held in place by being cemented tothe upper tool 9'but it may be lsimilarly attached to the tool 3 if sodesired.

The operation is as follows: The motive power isapplied through theshaft 10 by means of the pulleys 24 and 25 in the usual manner. Theshaft 10 is given a longitudinal reciprocation by means of the screwgears 11 and 12 which operating through the eccentric link motion of theparts 1G and 18 cause the block 20, which is fiXcdly attached t0 theshaft, to carry the shaft back and forth in its bearings. The eccentricarm 26 which carries the upper tool is given a longitudinalreciprocation through the link motion just described and aI transversereciprocation through its eccentric connections 27-to the shaft 10. Thepath ot' the trailsverse reciprocations may be autoiiiatically variedthrough the connecting rod 48 operating through its eccentric adjustmentwith the'bolt 49 in the pivot bolt 5l which is progressively advanced by.means of the'oscillating arm 55 operating the pawls 54 and the ratchetwheel 53, as previously described. The amount of the variation of thispath depends on the eccentric adjustmentrof the bolt 49 in the slot 50on the pivot bolt 51.- vThe initial or starting position of the uppertool on the lower tool may also be arbitrarily varied in a transversedirection by means of the adjusting bolt 57 which operates theconnecting strap 32, engaging the tool holder.' The upper tool is sosecured to the eccentric arm 26 that it is always held against the pivotpoint 35 ofthe pin 34 and will travel withthe arm 26 when the same islifted about its pivot on the shaft 10. The upper tool is also held inparallel' alinement with r thevlower tool by means of the spring forks37 and may adapt itself to the contour of the lower tool through theoscillating connectionsof the said forks, as previously described.

To place a lens in position to be ground the eccentric arm 26 is liftedpivoting around the shaft 10o This arm may be liftedeither by the handle29 or by the handle 61, as desired, the only-dilference being that ifhandle 6l is used the arm 26will rest on the oifsetcrank 59 and remainin its raised position. The lens 67 iscemented to the upper tool' 9which is placed between the spring forks 37, as previously described.The abrasive mixture is then applied between the lens and the lower tooland the arm 26 lowered, the pointed end of the pin 35 engaging therecess 36 in top of the tool 9 and holding l it in place on the lowertool through the pressure of the spring 64;. Thepower is then. appliedand the lens 67 is reciprocated across the lower tool by means of themecha nism previously described, the lens remaining in parallelalinement with the lower tool during this operation.

It will be noted that-the lens may be lifted with the upper tool 9' offof the'lower tool whenever desired by raising the arm 26, which willfacilitate the supplying of the abrasive material as it becomesexhausted, and permit the progress of the grinding to be examined at WilIt will also be'noted that the lens and upper tool may be thrown out ofcontact with the lowertool.while the machine is in motion or operating,by thro-wing up the ofi'- set crank 59 by means of the handle 61, thuspern'iitting the Work to Je examined or the abrasive material tof besupplied without stopping the movement of the machine, which isconsidered quite an`advantage in a mechanism 0f this kind.

It will also be noted that the amplitude ofthe longitudinalreciprocations may be adjusted independently of the transversereciprocations, being arbitrarily adjusted, and

the transverse reciprocations being both arbitrarily andautomaticallyadjustable.

It will also be seen that by properly selecting the number of teeth' inthe feed ratchet wheel 53 and by making a proper gear ratio inthe screwgears 11 and 12, which should not be multiples of each other, the pathof the upper tool over the lower tool will be broken up and it will beatvery rare intervals that a given point in the-lipper tool will repeatits path over the` lower tool, which is a very desirable feature in thegrinding of lenses, as it prevents grooves from being worn` into theirsurfaces, and insures a smooth and even polish as well as distributingthe wear uniformly over the lower tool. n

Thearrangements shown in Figs. III and lV permit the ready change of thelower tools of various curvatures and facilitate the work in allowingchanges to be made from y one form to another, it only being necessary lclaim as new therein and desire to secure by Letters Patent is: f

l. In a machine of ethe character described, the drombination withmembers to grind alens held betweensthem, of means for shifting one ofsaid members in a serpentine path relative to the other, the saidshifting means including a variable length arm and suitable arm shiftingmechanism, an eccentric coupled with the variable length arm, andmeanslfor var-'ying the position of the eccentric and thus the length ofthe arm, whereby the limits of the ser- `peutine path Aare variedproportional lto the variance in length of the arm, substantially asdescribed.

2. In a machine lof the character described, the combination with agrinding member and a lens holder, of a variable length arm engaging oneof said members, means for reciprocating the arm and member engagedthereby as a whole, and a driven eccentric coupled with the variablelength arm and serving to expand or con-v tract the length of the arm tovary the path covered by the member engaged by the arm duringreciprocations of the saine amplitude.

3. The combination with grinding members adapted'to grind a lens heldbetween them, of airotatablyendwise slidable shaft 'farisei operativelyconnected with one of the grind- 4 ing members, a block on the shaft,intermeshing gears one of which is mounted on the shaft, and aneccentric link gear uniting lthe gear remote from the shaft with theblock so as to slidably operate the vshaft in its journals.

4. The combination with grinding members adapted to grind a lens heldbetween them, of a shaft operatively connected with one of the grindingmembers, a' block on said shaft, intermeshing gears, one of which ismounted von the shaft, and an eccentric link gear uniting the gearremote from the shaft with the block so as to slidably operate the shaftin its journals, and means for arbitrarily Xing the limits within whichthe shaft is slidably operative. v

5. In a lens grinding machine, the combination with a power transmissionarm and means for actuating the arm, of a supplemental section carriedby the'arm and terminating in a contact point for engaging a block orlap, a rotatably mounted eccentric, means for rotating the eccentric,and a connection between the eccentric and the supplemental member,whereby actuation of the eccentric through the connection shifts thesupplemental section to vary the relation of its point to the arm,substantially as and for the purpose described.

6. The combination with grinding membersadapted to grind a lens heldbetween them, of a shaft, an eccentric transverse re ciprocating armoperatively engaging the shaft, a rockeraarm ypivoted on thereciprocating arm and operatively engaging one of the grinding members,and means onthe transversey reciprocating arm for operating the rockerarm so as to automatically vary the path of the transversereciprocations transmitted by the reciprocating arm.

7. The combination with grinding members adapted to grind a lens heldbetween them, of a shaft connected' with one of the grinding members bya' transverse reciprocating member, means for automatically varying thepath of the transverse reciprocations comprising an oscillatingarm-pivote'l on the transverse reciprocating member and non-rotatablyengaging the shaft, pawls on the oscillating arm, a ratchet wheeljournaled on the transverse reciprocating member and' adapted to engagethe pawls, a connecting rod operatively engaging one of the grindingmembers, and means transmitting motion from the ratchet wheel `to theconnecting rod.

8. The combination with grinding members adapted to grind a lens heldbetween them, of a shaft Iconnected' with one of the "grinding membersby a transverse reciprocatiiig member, means for automatically varyingthe path of the transverse reciprofor v "cations comprising anoscillating arm pivotedx on the transverse reciprocating member andnon-rotatably engaging the shaft,

pawls on the oscillating arm, a ratchet wheel journaled on thetransverse reciprocating member and adapted to engage the pawls,`aconnecting rod operatively engaging one of the grinding members, meansfor transmitting motion from the ratchet wheel to the connecting rod,and arbitrary means for fixing the limits Within which the means forautomatically varying the path of the trans verse reciprocationsoperate.

9. The combination with grinding meribers adapted to grind a lens heldbetween them, of a shaft connected with one of the grinding members by atransverse reciprocating member and means for automatically varying thepath of the transverse reciprocations comprising an oscillating armpivoted on the transverse reciprocating member and non-rotatably heldagainst the shaft, a connecting rod operativelyen aging one of thegrinding members, an an intermittently operating feed gear operativelyconnecting the oscillating army and the connecting rod.

l0. The combination with grindin members adapted to grind a lens heldetween them, of a shaft connected with one of the grinding members by atransverse reciprocating member, a rocker arm pivoted on thereciprocating member and operatively engaging one of the grindingmembers, an eccentric coupled with the rocker arm, and means foractuating the eccentric for oscillating the rocker arm and fixing theinitial position of the grinding member engaging the rocking arm withrespect to the other grinding member.

11. In a machine of the character described, tlie combination withmembers adapted to grind a lens held between them, of mechanism forimparting a relative movement compounded oflongitudinal and trans-IVverse reciprocations to the said members said means including anextensible sectionai Aarm having engagement with one of the members, anintermittently operating rotatably mounted eccentric, means for rotatingone of the grinding members by a transversek reciprocating member, arocking arm pivotefl on the reciprocating member and operativelvengaging thegrinding member, a divided connecting arm having one endpivoted to the reciprocating member and the other to the rocker arm, andadiustable means uniting the divided parts ot the connecting arm wherebylthe distance between them mayv be varied and the rocher arm positioned.Y,

18. The combination with grinding membersadapted'to grind a lens heldbetween them, of a sha t operatively connected. with onel of thegrinding members bv a t ans-verse reciprocating member, a rocker armpivoted thereon and having a pointed portion plvotally seated in arecess of the grindingmember, a spring fork pivotally attached bothtothe reciprocatingfarm and to the grinding member and yielding meansadapted to draw the spring forli toward the reciprocating arm andpreserve the contact of the pointed portionof the rocker arm in thesocket of the grinding member.

14. The combination with grindingmein'- lbers adapted to grind a lensheld between l them, of a reciprocating member operatively connectedwith one of the grinding members and means for adapting thereciprocating grinding member to the curvature of the other grindingmember and holding it in parallel alinement therewith, connarising arockery arm pivoted to the reciprocating member, a block pivoted to therocker arm and a spring fork pivoted to the block at one end andpivotally embracing the grinding member at the other substantially asshown and described.

15. The combination of a grinding mem ber having a socket, a. pedestal,a dog pivoted on the pedestal. and means for throwing the dog in and outof engagement with the socket inthe grinding member.

16.' The combination of a grinding member having alocking socket, apedestal, means pivot.

19. The combination of a pivoted reciproeating arm, a lift bartransversely disposed to the arm and means for operating the litt barwhereby it will move the reciprocating arm about its pivot withoutinterrupting its reciprocations.

20. The combination 'of pivoted reciprocating arm, lifting means, meansfor operating the lifting means whereby it will move thereci irocatinrfarm about its pivot with-V out linterr opting its reciprocations.

niemeer 2l. The combination of a pivoted reciproeating arm. liftingmeans, means for operatingthe lifting means whereby it will move Vthereciprocating arm about its pivot Withbers adapted to grind a lens heldbetween them, of a pivoted reciprocating arm, a grinding. memberoperatively engaging the reciprocating arm, means adapted to hold thegrinding tool on the reciprocating arm as it is moved on its pivot, andyielding means for holding the grinding members t0- gether underpressure. i

24. Thecombination of a main shaft slidably .mounted in journals on theframe; a gear on the shaft, a gear journaled on the frame and meshingwith the gear on the shaft, a block on the shaft and turning therewith,a yfork lever pivoted to the frame and having bifurca-ted membersengaging an annular groove in the block on the shaft, a slot in the faceof the gear mounted on the frame, an adjustable shoe in the slot, a linkpivoted to the shoe at one end and t0 the bifu cated lever at the otherand means `for locking the shoe in position in the slot so as toregulate the eccentric movement of the bifurcated lever and theconsequent reciprocation of the driving shaft in its journals. l

rThe combination with grinding members adapted to grind a lens heldbetween them, of a main shaft, eccentrics on the main shaft, atransverse reciprocating arm operatively engaging the ecccntrics, arocker arm pi voted on the reciprocating arm and having a. pointedmember pivotally engaging socketin one of the grinding members, aconnecting rod substantially parallel with the reciprocating arm andhaving one end pivoted to a bearing on the said arm and the other endpivotally engaging the rocker arm, an oscillating arm having oneendhheld on the main shaft and the other end pivoted to an integralbearingon the reciprocating arm, pawls on the oscillating arm, a ratchetwheel journaled in the integral' bearing on the reciprocating arm andengaging the pawls, a pivot pin in the bearing on the reciprocating armunitingthe ratchet wheel and the end of the connecting rod, and means onthc pivot pin` for eccemrically 4adjusting the end of the connecting rodand regulating the throw of the rocker arm pivoted at Athe other end ofthe reciprocating arm. 7

2G. The combination with grinding members adapted to grind a lens heldbetween them, of a main shaft, eccentrics on the main shaft, a'transverse reciprocating arm operatively engaging the eccentrics, arocker arm pivoted on the reciprocating arm and having a pointed memberpivotally engaging a socket in one of the grinding members, a connectingrod substantially parallel with the reciprocating arm and having one endpivoted to a bearing on the said arm and the other end pivotallyengaging the rocker arm, an oscillating arm having one end held on themain shaft and the other end pivoted to an integral bearing on thereciprocating arm, pawls on Vthe oscillating arm, a ratchet wheeljournaled in the integral bearing on the reciprocating arm and engagingthe pawls and a pivot pin in the bearing on the reciprocating armuniting the ratchet wheel and the end of the connectingrod.

27. The combination of a reciprocating arm, a rocker arm pivoted on thereciprocating arm, a pin bearing on the rocker arm, a grinding member`having a recess adapted to engage the pin bearing, a second rocker armpivoted to the reciprocating arm, a block pivoted to the second rockerarm, and a spring fork pivotally engaging the grinding` 'member at oneend and the block at the other and a spring connecting the spring forkand the reciprocating arm so as to hold the grinding member against thepin on the rocker arm. i

2dr The combination with grinding members adapted to grind a lens heldbetween them, of a shaft operatively connected with one of the grindingmembers by a transverse reciprocating member, means on the reciproatingmember i'or reciprocating the grinding member in unison with andvariably with respect to the reciproeations oit the transversereciprocating member and means for resiliently holding the `grindingmember in engagement with the various reciprocating means `when thegrinding members are separated.

29. The combination with grinding members adapted to grind a lens heldbetween them, of a rotatable endwise slidable shafty operativelyconnected with one of the grinding members, a shift collar on the shaft,1ntermeshing gears one of which is mounted on the shaft and theotherjvifn a suitable support, a. support having a'fjrojection adjacentthe latter gear, a shift yoke having one end fulcrumed to the supportand the other engaging the shiftrollar on the shaft, and a linkeccentrically pivoted to the gear on vthe support and having its otherend pivoted to the shift yoke, whereby as the gear is rotated the `linkoperates the nally shift the shaft.

30. The combination with a support, of ayoke tolongitudi-4 forlipivotally supported thereby for uni- 7 versal movement with respectthereto, a tool carried 4by the fork, an arm pivoted to the support andengaging the tool, means for reciprocating the support and parts carriedthereby, and means operated by the reciproeating means for rocking thepivoted arm toshift the tool relative to the support.

31. The combination with a support, of a fork pivotally supportedthereby for universal movement relative thereto, a tool carried by thefork, an arm pivoted to the support and engaging the tool, means forre-l fork pivotally supported thereby for universal movement relativethereto, a tool carried by the fork, an arm pivoted to the support andengaging the tool, means for reciprocating the support and parts'carriedthereby, means for longitudinally moving the entire device to serve inconjunction with the reciprocating means to impart a sinuous movement tothe tool, and means operated by the reciprocating means for rocking thepivoted arm to shift the tool relative to the support to cause the toolto have a diagonally directed sinuous movement.

33. The combination with a rotatable shaft, of an eccentric secured onthe -shaftfor rotation therewith, a support having an eccentric strapengaging the eccentric, a tool arm pivoted tothe support, and meanspivoted to the support and vconnecting the tool arm with the shaft torock the arm relative to the support as the support is reciprocatedthrough the action of the eccentric uponrotation of the shaft.

y341i. In a grinding machine, the combina-,

tion. with a lens holding member anda lens grinding member, of -a powershaft, and three eccentrics having driving connection therewith,,connections between one of the vfirst mentioned members and one oftheercentrics-for imparting a transverse reciprocation to the member,connections between one of the members and a second of the eccentricsfor imparting a longitudinal reciprocation to said member, andconnections betricelly'lo'cated driving members in operative connectionwith said shaft, connections between two of said devices and one of thelens holding or grinding members for longitudinally reciprocating saidmember at one rateandlfor transversely reciprocating it at ma differentrate, Wherebysaid member is relatively shifted in a Varying curve pathlying Within a predetermined zone, and connections between another ofsaid eccentri,n cally disposed membersand the Yholding or grindingmembeifor supplementally reciprocating it at a different rate andrelative to one of the other reciprocating movements imparted to it,whereby said last mentioned reciprocations progressively vary the limitsof the `zone in which the member is operated.

36; In a grinding machine, the combination with a lens holding memberand a lens grinding member, of a plurality-of' driven eecentrics,connections between one of the eccentrlcs and one of the members forlongitudinally reciprocating said member at a fixed rate,v connectionsbetween another of the eccentrics and one of the members fortransversely reciprocating the member at a different rate, anintermittently operated eecentric, and connections between saideccentric and one of the grinding members for intermittently impartingan additional movement to said member to break np theI con; tinuity ofthe path of relative movement of the lens holding and grinding members.

In testimony whereof we alix our signa. tures in presence of twowitnesses.

GEORGE H. DAY.

, LUCIAN W. BUGBEE.

Witnesses: i e PAUL T. TRUEMAN, REGINALD H. WATERS.

